When compared to liquid crystal panels, high speed display is possible with plasma displays (PDPs) and, furthermore, it is easy to produce large sizes, so they are used in fields such as OA equipment and advertising display devices. Moreover, advances into fields such as high quality televisions is greatly expected.
Along with such broadening of applications, colour plasma displays with numerous fine display cells are attracting attention. Now, taking an AC type plasma display as an example for explanation, plasma discharge is produced between facing anodes and cathodes within discharge spaces provided between a front glass substrate and a rear glass substrate, and the ultraviolet rays generated from a gas sealed within these discharge spaces strike phosphors provided within the discharge spaces, thereby producing the display. A simple structural view of an AC type plasma display is shown in FIG. 1. Here, barrier ribs (also referred to as barriers or ribs) are provided to keep the spread of the discharge within fixed regions and to carry out display within prescribed cells, and also at the same time to secure uniform discharge spaces. In the case of an AC type plasma display, these barrier ribs are formed as stripes.
The barrier ribs are roughly of width 30-80 .mu.m and height 70-200 .mu.m and, normally, they are formed to a specified height by the printing of an insulating paste containing glass powder on the front glass substrate or the rear glass substrate by a screen printing method and then drying, and repeating this printing and drying process 10 or more times.
In Japanese Unexamined Patent Publication (Kokai) Nos 1-296534, 2-165538, 5-342992, 6-295676 and 8-50811, methods are proposed for forming the barrier ribs by photo-lithography using a photosensitive paste.
By all of these methods the barrier ribs are produced by forming an insulating paste containing glass powder in the shape of the barrier rib pattern, and then firing. In such circumstances, due to differences in the firing shrinkage between the upper and lower regions of the barrier ribs, there has been the problem that the ends of the barrier ribs separate from the substrate and spring up as shown in FIG. 4, or the upper portion of the barrier rib swells upwards without separation as shown in FIG. 5.
Where this springing or swelling upwards is at the ends of the barrier ribs, a gap is produced between the front plate and the peaks of the barrier ribs on the rear plate when the front plate and rear plate are brought together and the panel formed. As a result of such a gap, there has been the problem that cross-talk occurs at the time of discharge and disturbance is produced in the picture.
To remedy this, in Japanese Unexamined Patent Publication (Kokai) No. 6-150828 there is proposed the method of giving the barrier ribs a multilayer structure, with the compositions of the upper and lower layers altered, and providing in the lower layer a glass of lower melting point than in the upper layer. Again, in Japanese Unexamined Patent Publication No. 6-15083, there is proposed the method of providing an under glass layer on the underlayer at the ends. However, none of these methods has been adequate in terms of preventing the swelling. Again, in Japanese Unexamined Patent Publication No. 6-150832, there is described a method in which the barrier rib ends are given a stepped form, but the prevention of swelling is inadequate.